<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
        <button id="but">点我呀</button>
</body>
<script>
    document.getElementById("but").onclick=function(){
        alert("点我干嘛");
        prompt("提示内容")
    }
</script>
</html>